Metabolomic fingerprint of Mentha rotundifolia L. Leaf tissues promotes this species as a potential candidate for sustainable production of biologically active molecules.

Background The Mentha rotundifolia L. (Lamiaceae family), is a medicinal herb used since the ancient times as an antiseptic, analgesic and anti-inflammatory agent. In the present work, metabolomic profiling of two Mentha rotundifolia L. ecotypes leaf tissues spontaneously growing in the North of Tunisia was achieved. Methods Phenolic contents (TPC, TFC and TTC) were assessed using colorimetric methods. Metabolomic profiling of leaf tissues extracts was assessed based on Gas Chromatography-Mass Spectrometry (GC/MS) analysis. The antioxidant ability of M. rotundifolia extracts was achieved based on two test systems namely DPPH and FRAP assays. Antimicrobial activity against a set of Gram negative and Gram positive bacteria was estimated by measuring ID, MIC and MBC values. Results Fifty metabolites were identified as belonging mainly to phenolics, fatty acids, terpenes, steroids and aldehydes classes with qualitative and quantitative variability. Most of the identified compounds are reputed bioactive with potent antioxidant, antimicrobial and anti-inflammatory among others effects. To confirm these findings common in vitro biological activities were achieved. The investigated extracts showed significant antioxidant abilities based on both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Ferric reducing antioxidant potential (FRAP) assays. Furthermore, the extracts revealed promising antimicrobial ability against tested Gram+ and Gram- bacterial strains (ID: 12.5-14.5 mm, MIC: 3.125-25 (µg/mL), MBC: 6.25-100 (µg/mL)). Conclusions Based on our findings Mentha rotundifolia L. leaves extracts present a potential source of natural antioxidants and diverse bioactive compounds which could be used in green pharmacy, food preservation, alternative medicine and natural therapies.